Microfluidic technology is revolutionizing biological research and medical diagnostics by reducing analyte and reagent volumes, allowing massive parallelization, and enabling the integration and automation of multiple processes in single devices. Advances in active micro valves using multilayer soft lithography have laid the path to large scale integration of microfluidic components such as valves, pumps, and other active components into full analytical systems. However, the complexity and cost of the control hardware is still a limitation: although a single external control line may be used to control thousands of valves, current microfluidic technologies still require one dedicated external control line for each independently actuated set of valves. This imposes a practical limit on number of independent control operations that can be integrated on to a lab-on-a-chip device and poses a scalability problem.
Microfabricated fluidic chips may be used for biological assays. For example, microfabricated fluidic chips may be used to perform biological assays using external control lines that control the opening and closing of on-chip fluidic valves. The on-chip fluidic valves control the flow of fluids in biological assays. The valves are opened and closed using macroscopic pressure sources that are located off-chip, and which are connected through control lines to the chip. In complex assays, a large number of macroscopic control lines is cumbersome and undesirable. Previously known electrical actuating means built into chips have not been able to provide sufficient force by themselves to open or close fluidic valves in practical situations (e.g., handling liquids at 1-10 psi).
It would therefore be desirable to provide pressure sources and control lines on-chip that control the opening and closing of on-chip valves so that macroscopic control lines exiting the chip are minimized or eliminated. Previously known on-chip systems have not been adequate to provide control of numerous on-chip valves. Therefore, there is a need in the art for improved methods and systems related to microfluidic devices that can provide logic functionality.